- Light travels very, very fast. The speed of light in a vacuum (an area empty of matter) is around 186,000 miles per second (300,000 kilometres per second).
- Light travels slower through different mediums such as glass, water and air. These mediums are given a refractive index to describe by how much they slow the movement of light. Glass has a refractive index of 1.5, meaning that lights travels through it at around 124,000 miles per second (200,000 kilometres per second). The refractive index of water is 1.3 while the refractive index of air is 1.0003, meaning that air only slightly slows down light.
- Light takes 1.255 seconds to get from the Earth to the Moon.
- Sunlight can reach a depth of around 80 metres (262 feet) in the ocean.
What is light ?
Light is part of the electromagnetic spectrum, the spectrum is the collection of all waves, which include visible light, Microwaves, radio waves ( AM, FM, SW ), X-Rays, and Gamma Rays.
What we record in photography is limited by the process. Whereas our eyes can see a spectrum of colour, hues and tone in the real world a camera will become confused and only record some of the same view. This is because camera have a limited Exposure Value (EV).
An image with too much contrast or varying velocities cannot capture it all, as the eye can. The artistic choices that use these limitations is the 'art' of photography, or Drawing with Light.
An image with too much contrast or varying velocities cannot capture it all, as the eye can. The artistic choices that use these limitations is the 'art' of photography, or Drawing with Light.